1. Technical Field
The present invention relates to a technique of displaying right-eye image and left-eye image having a mutual parallax effect so that an observer can perceive a stereoscopic effect.
2. Related Art
Hitherto, frame sequential type stereoscopic viewing methods of alternately displaying the right-eye image and the left-eye image in a time-division manner have been suggested. In a period in which one of the right-eye image and the left-eye image is changed to the other thereof, the right-eye image and the left-eye image are merged. Therefore, when a viewer views the right-eye image and the left-eye image, it may be difficult for the viewer to perceive a clear stereoscopic effect (crosstalk). In order to resolve this problem, for example, JP-A-2009-25436 discloses a technique of closing both right-eye shutter and left-eye shutter of stereoscopic viewing glasses in a period (that is, a period in which the right-eye and the left-eye image are merged) in which one of the right-eye and the left-eye image is changed to the other thereof, so that a viewer may not perceive the right-eye image and the left-eye image.
Specifically, as shown in FIG. 12, a right-eye period corresponding to the right-eye image and a left-eye period corresponding to the left-eye image are alternately set. A display image is updated from the left-eye image to the right-eye image in the first-half period of the right-eye period and the right-eye image is displayed in the second-half period of the right-eye period. The display image is updated from the right-eye image to the left-eye image in the first-half period of the left-eye period and the left-eye image is displayed in the second-half period of the left-eye period. In the first-half period of each of the right-eye and left-eye periods, both the right-eye shutter and left-eye shutter are controlled so as to be in the closed state. Accordingly, it may be difficult for the viewer to perceive the merging (crosstalk) of the right-eye image and the left-eye image.
In the technique disclosed in JP-A-2009-25436, however, the period in which the viewer can actually perceive the image is restricted to the second-half period (that is, about half) of each of the right-eye and left-eye periods. Accordingly, a problem may arise in that it is difficult to sufficiently ensure the brightness of the display image. Further, to realize a stereoscopic (3D) display process of alternately displaying the right-eye image and the left-eye image, the transmission speed of an image signal and the process speed of a driving circuit has to increase the speed of a planar (2D) display at the frame frequency of image display by double or more. Therefore, a problem may arise in that the circuit size or the manufacturing cost of the driving circuit increases.